Tweener.addTween(page1Content, {alpha:0, x:-266, time:1, onComplete:hidePage1Content});
See how lunky that is at the end? I really don't want to have to write a whole function just to turn the thing off, but there isn't a way around that given the timing of Tweener. It HAS to wait until the Tween is complete. So, after a bit of thinking and digging I was able to add an inline function to do this for me and save me some function writing. This is what I ended up with:
Tweener.addTween(page1Content, {alpha:0, x:-266, time:1, onComplete:function() { this.visible = false; }});
Now the inline function runs right after the content fades out with no additional function writing necessary.
Easy!